Cutting 8-inch steel with a torch - GIF

[Jon]

Cutting 8-inch steel with a torch.

[Ralphxyz]

Is that a gasoline fueled torch?

Ralph

[Frank S]

Cutting anything that thick would almost have to be Map or natural gas, could be done with acetylene as long as it was a 6 or 12 pack manifolded system the torch we had in Kuwait had 9 straight line torches on the back 2 planetary & 1 1200 amp Plasma torch . 9 torches cutting strips out of a 40 ft long 10 ft wide 2" plate would suck 3 12 packs dry in a day's time 1 of acetylene 2 of oxygen would have used compressed natural gas but couldn't get a permit for large enough storage
thickest we ever cut was 4 inch on the 2 planet torches and 2 inch on the 9 straight-line the plasma would cut 4 inch but you couldn't get a true vertical cut on all sides

[NortonDommi]

The head looks a long way away from the cutting surface. How is the gas stream held straight? Must be some high pressure behind it surely? I've hand cut 6" but I always have torch head within an inch of surface,(preheats just shy),and have found that cut gutters if torch is raised.

[Frank S]

The head looks a long way away from the cutting surface. How is the gas stream held straight? Must be some high pressure behind it surely? I've hand cut 6" but I always have torch head within an inch of surface,(preheats just shy),and have found that cut gutters if torch is raised.

Yes that is all the more reason for my assumption of the type of gas being used for pressure I would suspect oxygen heat pressures in the range of 45 to 60 PS with the gas pressure upwards of the 30 to 4 PSI range while the cutting pressure probably coming in around 150 PSI. having the head that high would cut down on surface remelt
Did you happen to notice how small the kerf was relative to the thickness. To me the kerf appeared to be more along the lines of being proportional to cutting 3 inch or less . I am wondering how much bottom pre heat was used. I knew a guy who had a custom burning business back in the day of optic eye torches who had cut his mane out if a 4" cube in Chinese he owned 3 6 head and 2 3 head torches and it wasn't anything to see him burning on all 5 machines at the same time by himself. best burner I ever knew

[user name blacksmith]

I was in a mine truck mfg.company in Billings Mont.in 1992,and had a 6" piece of steel cut from a 4footX4foot block.The guy that cut it used acetylene& oxygen to preheat the starting cut then after it started to cut he turned off the acet. and just used the 02 at about 60-70 psi. He said once the cut was hot enough it didn't need the gas, if you didn't travel to fast. this was done on a computer controlled table,it was damn near perfect. BLF.